Puzzled. People, who judge it unethical to contemplate herd immunity from natural infection, argue it's uncertain how long immunity lasts. But natural immunity is probably better than vaccine immunity. If natural immunity doesn't last, then vaccines won’t work either. What then?
I'm not arguing that we should let the virus take its course. I certainly think we should shield the vulnerable until a vaccine is available. But I don't see we can vaccinate everybody in the world, perhaps yearly. We haven't managed to eliminate measles; it only takes one shot.
In addition, "Vaccines will not be proven to be safer for children and young people than the infection for some years, if ever". bmj.com/content/370/bm…
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Skal alle danskere vaccineres mod COVID-19? Baseret på hvad vi ved, er mit svar et klart nej. Her mine tanker.:1) Diskussionen er for tidligt ude. Vi har ikke en vaccine endnu. Vi har aldrig skabt en effektiv vaccine mod Corona-virus. Vi har ventet >35 år på en HIV-vaccine.1/8
2) Hvis vi får en vaccine, ved vi ikke, hvor mange doser, der skal til for at give beskyttelse. "Ikke-levende” vacciner skal man typisk have 2-3 doser af for at opnå immunitet. 3) Vi ved ikke, hvor længe beskyttelsen varer, det kan være som influenzavaccine: en ny hvert år. 2/8
4) Baseret på ovenstående kan vi risikere at en strategi med at vaccinere alle danskere er dyr og ineffektiv. 5) Dertil kommer sikkerheden. Med en ny vaccine er der risiko for bivirkninger. Den hidtil hurtigst udviklede vaccine tog 4 år at udvikle. Her er vi under tidspres. 3/8
ORAL POLIO VACCINE (OPV) – SOME CLARIFICATION. I’m a big OPV fan, but when I write about OPV I get negative feedback. So time to go through why I’m a fan and explain why I don’t see the same problems as some people do. Ready to get assumptions challenged? Follow this thread (1/n)
OPV was developed in the 1950s. At that time, polio was a problem. Epidemics followed epidemics, and though most people had asymptomatic disease, at its peak in the 1940s and 1950s, polio would paralyze or kill over 500,000 people worldwide every year (2/n)
After the introduction of the two polio vaccines, OPV and the inactivated polio vaccine (IPV), the incidence decreased. Cases due to wild poliovirus decreased by over 99% since 1988, from an estimated 350,000 cases then, to 33 reported cases in 2018 (3/n) who.int/en/news-room/f…
In 2015, the RTS,S Clinical Trials Partnership published the results of a Phase-III trial of RTS,S malaria vaccine, including 6537 infants (6-12 wks) and 8922 children (5-17 mo). RTS,S gave 18% (infants)-36% (children) protection against clinical malaria. ncbi.nlm.nih.gov/pubmed/25913272
The authors wrote that there was no significant vaccine efficacy against allcause mortality". @EMA_News approved the vaccine. But based on the numbers in the appendix, we calculated that the vaccine was associated with 24% (95%CI=-3-58%) higher mortality. thelancet.com/journals/lance…